Silicon anodes are considered to have great prospects for use in batteries;however,many of their defects still need to be improved.The preparation of hybrid materials based on porous carbon is one of the effective way...Silicon anodes are considered to have great prospects for use in batteries;however,many of their defects still need to be improved.The preparation of hybrid materials based on porous carbon is one of the effective ways to alleviate the adverse impact resulting from the volume change and the inferior electronic conductivity of a silicon electrode.Herein,a chain-like carbon cluster structure is prepared,in which MOF-derived porous carbon acts as a shell structure to integrally encapsulate Si nanoparticles,and CNTs play a role in connecting carbon shells.Based on the exclusive structure,the carbon shell can accommodate the volume expansion more effectively,and CNTs can improve the overall stability and conductivity.The resulting composite reveals excellent rate capacity and enhanced cycling stability;in particular,a capacity of 732 mA·h·g^(-1) at 2 A·g^(-1) is achieved with a reservation rate of 72.3% after cycling 100 times at 1 A·g^(-1).展开更多
Ti(C,N)nanoparticles were added to an Al-0.3 Ce alloy by ultrasonic treatment.Further annealing at 570℃for4 h afforded the ultimate tensile strength of 79 MPa and electrical conductivity of 64.0%IACS for the Al-0.3 C...Ti(C,N)nanoparticles were added to an Al-0.3 Ce alloy by ultrasonic treatment.Further annealing at 570℃for4 h afforded the ultimate tensile strength of 79 MPa and electrical conductivity of 64.0%IACS for the Al-0.3 Ce alloy with1.5 vol%Ti(C,N)addition.Both performance parameters were improved by 23.4%and 0.6%IACS,respectively,compared with those of casting refining pure aluminum(64 MPa and63.4%IACS).This could be explained by the following reasons.The addition of Ti(C,N)nanoparticles could significantly refine the grain of Al-0.3 Ce alloy.Notably,most of the coarse strip-shaped second phases distributed at the grain boundaries in Al-0.3 Ce were also transformed into spherical microparticles distributed in the grains,with micro-nano hierarchical structures comprising orientated nanosized strip phases with lengths of~400 nm and widths of~100 nm.Moreover,a fine micro-nano hierarchical spherical structure could be obtained after annealing at 570℃for 4 h.The numbers of micro-nano hierarchical spherical structures also increased due to the precipitation of pseudosolution Ce from the aluminum matrix during the annealing treatment.展开更多
基金financially supported by the“Light of West China”Program of the Chinese Academy of Sciences.
文摘Silicon anodes are considered to have great prospects for use in batteries;however,many of their defects still need to be improved.The preparation of hybrid materials based on porous carbon is one of the effective ways to alleviate the adverse impact resulting from the volume change and the inferior electronic conductivity of a silicon electrode.Herein,a chain-like carbon cluster structure is prepared,in which MOF-derived porous carbon acts as a shell structure to integrally encapsulate Si nanoparticles,and CNTs play a role in connecting carbon shells.Based on the exclusive structure,the carbon shell can accommodate the volume expansion more effectively,and CNTs can improve the overall stability and conductivity.The resulting composite reveals excellent rate capacity and enhanced cycling stability;in particular,a capacity of 732 mA·h·g^(-1) at 2 A·g^(-1) is achieved with a reservation rate of 72.3% after cycling 100 times at 1 A·g^(-1).
基金Panxi Strategic Resources Innovation Development Fund of Sichuan Province(No.1840STC30704/01)。
文摘Ti(C,N)nanoparticles were added to an Al-0.3 Ce alloy by ultrasonic treatment.Further annealing at 570℃for4 h afforded the ultimate tensile strength of 79 MPa and electrical conductivity of 64.0%IACS for the Al-0.3 Ce alloy with1.5 vol%Ti(C,N)addition.Both performance parameters were improved by 23.4%and 0.6%IACS,respectively,compared with those of casting refining pure aluminum(64 MPa and63.4%IACS).This could be explained by the following reasons.The addition of Ti(C,N)nanoparticles could significantly refine the grain of Al-0.3 Ce alloy.Notably,most of the coarse strip-shaped second phases distributed at the grain boundaries in Al-0.3 Ce were also transformed into spherical microparticles distributed in the grains,with micro-nano hierarchical structures comprising orientated nanosized strip phases with lengths of~400 nm and widths of~100 nm.Moreover,a fine micro-nano hierarchical spherical structure could be obtained after annealing at 570℃for 4 h.The numbers of micro-nano hierarchical spherical structures also increased due to the precipitation of pseudosolution Ce from the aluminum matrix during the annealing treatment.
